Vehicle door lock actuator

ABSTRACT

Actuator for vehicle door locks provides powered shifting of a mechanism component while permitting manual operation thereof. A motor powers a driver annulus having internal teeth and notches in respective axial zones with each tooth being diametrically opposite a notch. A spring-loaded index across the annulus interior has a tail co-acting with the notches and a head co-acting with the teeth and is guided by fixed structure that it can only move angularly to displace the component to which it is linked, by indexing past a tooth when its tail is in a notch. Powered movement of the annulus causes the teeth to selectively shift the index, but manual displacement of the component causes the index to spring past the relevant tooth.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to locking systems for vehicle doors and otherclosures of the kind in which individual locks are interconnectedthrough a central control unit for electrical or other powered actuationwhereby locking or unlocking off some or all doors or other closures canbe effected from a single control station actuated from within oroutside the vehicle, herein referred to as "Central Locking Systems".The locking mechanism and associated power actuator will provide formanual operation whereby the respective door can be locked and unlockedusing a conventional interior sill button or other manually operatedinput element, and, maybe, by manual operation of a cylinder or otherkey controlled exterior lock.

2. Summary of Related Art

DE-A3319354 describes a locking system power actuator with facility formanual operation in which a powered driver has connection with an outputelement by way of an index resiliently urged into coacting engagementwith an indexing formation of the driver so that the output element ispositively indexed relative to the driver to one or other of its lockedand unlocked positions on manual operation, and powered displacement ofthe driver carries the output element between said positions.

OBJECT OF THE INVENTION

The object of the invention is to provide a power actuator which issimple and economical to produce and install, is durable and reliable inservice, compact and with few moving parts, which is quiet and efficientin use, and which contributes to efficient and effective manualoperation as well as powered operation.

SUMMARY OF THE INVENTION

According to the invention there is provided a power actuator forshifting vehicle door lock or other closure mechanism selectivelybetween a locked or other first condition and an unlocked or othersecond condition by powered operation while permitting manual operationalso for effecting said shifting, said actuator being distinguished bythe characterising part of appended claim 1.

Conveniently the driver is annular so that said first and secondabutment portions are constituted by generally diametrally opposinginterior wall portions of the annulus, the index being received withinthe annulus and the powered movement of the latter being rotational,i.e. said first path of movement is circular about the axis of theannulus.

Said annulus is conveniently powered by an electric motor having a wormpinion engaging an externally toothed periphery of said annulus.Preferably the helix angle of the worm pinion is selected to permitdriven rotation thereof by rotational force above a selected valueapplied to the annulus to enable manual release of the mechanism in theevent of a failure of power operation while the index is in positiveengagement between the annulus and output element.

The output element may be a lever one arm of which is directly orindirectly coupled to the index for movement therewith and said levermay be fulcrumed co-axially with the annulus or upon an axis spaced fromthe axis of the annulus and within or outside the envelope of revolutionthereof, whereby since second path of movement is angular.

The annular form of driver will preferably be provided with a series ofequi-angularly spaced teeth and notches right around its interiorperiphery, the teeth being in one axial zone of said periphery and thenotches, each being diametrically opposite a respective tooth, being inanother axial zone thereof, the head and tail of the index being instepped relationship in the diametrical plane for alignment with therespective axial zones.

The mounting will preferably include slots or other guide formationswith which control portions of the index engage to define thedisplacement of the latter during operation relative to the driver.

An example of the invention is now more particularly described withreference to the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a vehicle lock actuator,

FIG. 2 is an enlarged front elevation thereof in assembled condition butwith a housing cover and other parts removed, and

FIG. 3 is a diagrammatic section on line 3--3 of FIG. 2 but notincluding the housing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A power actuator 10 includes a housing base 12 which serves as a fixedmounting for other components and is provided with a mating cover 14.The housing contains an electric drive motor 16 having a worm pinion 18on its output shaft.

Pinion 18 meshes with the externally toothed periphery of a driver inthe form of an annulus 20, the axially rearmost part of which, as viewedin FIG. 1, is a collar 22 with a continuous cylindrical interior wallsurface journalled for rotation on a sleeve formation 24 of base 12.

The remaining axial extent of annulus 20 forwardly of collar 22 isdivided into two axial zones, a first axially median zone 26 adjoiningcollar 22 being provided with equi-angular spaced radially extendingnotches 28, (in this example six in number). The second and axiallyouter zone 30 adjoining zone 26 is formed to provide a series ofequi-angularly spaced radially inwardly projecting teeth 32 equal innumber to notches 28, i.e. six in this example, the tip of each toothbeing angularly coincident with a respective notch 28 so that there is asaid notch diametrally opposite each said tooth, but axially offsettherefrom.

Teeth 32 have flat side faces with an included angle, in this example,of about 130° and the gaps or valleys between each pair of adjacentteeth 32 therefore has an included angle of about 75° giving slopesproviding a camming action referred to hereafter.

Located within annulus 20 is an index 40 guided for restricted floatingmovement relative to the annulus as further described below. Index 40 isa generally elongate formation having a head 42 at one end and a tail 44at the other end, the overall length being greater than the internaldiameter of annulus 20 clear of teeth 32 and the lands between notches23 by approximately the depth of said notch (which is substantiallyequivalent to the depth of the valleys or gaps between teeth 32).

Head 42 is profiled and axially disposed to coact with the side faces ofteeth 32 and engage in the gaps therebetween and tail 44 is axiallyoffset inwardly as viewed in FIG. 1 to clear teeth 32 and is profiled toenter notches 28.

Tail 44 includes a rearward extension projecting into collar 22 andconstituting a control peg 46 engaging a radially extending control slot48 of base 12, defined by a radially inwardly extending pocket of sleeveformation 24.

The index also includes a stop 50 projecting rearwardly like peg 46 butremote therefrom near head 42. Stop 50 co-acts with a limit formation 52of base 12 within the upper half sleeve formation 24 as viewed in FIG.1.

Limit formation 52 has a pair of spaced buffers 54 which limit sidewaysswinging of head 42.

Index 40 can thus pivot about the axis of control peg 46 angularlyacross the centre of annulus 20 to an extent limited by contact of stop50 with the limit formations 52 and can also be displaced longitudinallyor near longitudinally by radial movement of control peg 46 along slot48.

An output element in the form of a two part bell crank lever 60, 62 isfulcrumed on a stub shaft 64 of base 12, a journal portion 66 of firstarm 60 of said lever including a splined projection 68 which extendsthrough cover 14 on assembly and mounts a second arm 62 of the leverexternally of the housing.

First arm 60 extends generally upwardly as seen in FIG. 1 to lie acrossthe outer end of annulus 20 overlying index 40. A longitudinal slot 70in the distal end of arm 60 engages an outwardly projecting crank pin 72at the head end of index 40. A compression spring 74 locates in slot 70and bears on the radially inner side of pin 72, so resiliently urgingindex 40 upwards as seen in FIG. 1, i.e. urging head 42 into engagementwith an abutment portion of annulus 20 constituted by the immediatelyadjacent peripheral wall with a respective tooth or teeth 32.

In use arm 62 of lever 60 will be linked to associated locking mechanismof the vehicle door or other closure. Said mechanism will also includeprovision for its manual operation, e.g. by an interior sill button ofthe door, in known manner for locking and unlocking, said operationcausing angular displacement of lever 60 between first and second, i.e.locked and unlocked, positions, arm 60 being displaced to one side ofthe other of the axis of annulus 20 by said operation.

In the course of such manual displacement head 42 of index 40 which isbeing urged upwards by spring 74 will ride or cam across the co-actingtooth 32 of annulus 20 from the valley or gap at one side thereof to theequivalent valley or gap at the other side, the force of spring 74serving to positively index lever 60 to the locked or unlocked position,helping it on its way by said camming action as soon as the head haspassed the mid-position crossing the radially inwardly projecting tip ofthe relevant tooth. During said movement the notch 28 which isdiametrally opposite said tooth allows tail 44 of index 40 to moveradially outwardly guided by control slot 48 and the index will also beswung angularly about its control peg 46 between the limits determinedby buffers 54. This manual operation can take place in either direction.The indexing effect gives a positive feel to the manual operationwithout involving excess loading or strain, and ensures that themechanism is fully shifted into and retained at the selected locked orunlocked condition until a further operation takes place.

If powered operation of the locking mechanism is to take place motor 16will be energised for drive in whichever direction is appropriate forthe relevant change of condition, the system including switches in knownmanner to detect and set the required sequence, so rotating annulus 20in the direction required for movement of lever 60 from whicheverposition it is at to the other position. Rotation of annulus 20 carriesthe lowermost part of its peripheral wall as viewed in FIG. 1, whichconstitutes an opposing or second abutment relative to the upper orfirst abutment mentioned above, past the tail 44 of index 40 so that aland between notches 28 is aligned therewith and blocks downwarddisplacement of the index. This prevents head 42 from being cammeddownwardly by co-action with teeth 32, it must remain in engagement withthe relevant inter-tooth valley or gap so that it is carried angularlywith annulus 20 and positively drives arm 60 and hence the lockingmechanism from one position to the other.

Once the mechanism has been power actuated to the selected condition,movement being limited by the relevant buffer 54, drive ceases and theindex will again be positioned with tail 44 aligned with a notch 28permitting manual operation in the reverse direction if required, or afurther power operation in the better direction.

The abutment faces of buffers 54 which are engaged by stop 50 are angledso that they tend to cam index 40 towards the first abutment constitutedby the relevant tooth valley while power driving force is appliedthereto, so ensuring that index 40 does not jump or start to jump thenext tooth 32 even though its tail is again aligned with one of thenotches 28.

It will be noted that no movement of annulus and its geared driveconnection to motor 16 takes place during manual operation, there is noback driving of a gear train or the like so avoiding noise and strain onthe mechanism when manual operation takes place. Nor is there any needfor a centrifugal, magnetic or other clutch in the drive train orrelated to motor with its problems of wear and unreliability, as isrequired in many conventional power actuators. Moreover, resilientlyloaded indexing is provided without the need for extra components suchas spring loaded toggle mechanisms or overcentre devices for thispurposes as is required in some known actuator mechanisms.

Conversely, under power operation, there is no involvement of theresiliently loaded indexing function, i.e. the power drive does not haveto overcome indexing loading as with many known actuators so requiringsubstantially less driving force and again reducing noise, wear andtear, and loading on components. Furthermore, conventional indexingpre-loads the mechanism so that excessive power is required to startmotion from rest and counter the contrary indexing force during thefirst half of travel which is trying to return the mechanism to itsstarting point. However, once the mid-point has been passed the indexingforce supplements the power input so that the final part of the travel,which has already built up speed in overcoming static inertia of thecomponents, is accelerated rapidly with maximum force just when it hasto come to a stop giving very noisy operation and substantial risk ofdamage or failure to components.

To guard against the possibility of the mechanism being jammed if poweractuation should fail in a situation where index 40 was not free to ridepast a tooth 32, worm pinion 18 is preferably formed with a helix anglewhich will allow back drive if lever 60 has manual driving force appliedto it above a predetermined level, but the mechanism can be manuallyreset to one or other conditions by applying somewhat more force thannormal, and can then be further operated manually or by power asreferred to above.

It will be appreciated that the output element can take various formssuch as a link guided for rectilinear movement or various types oflever, or lever and linkage combinations. For some applications a simplelever pivoted co-axially with the annulus can be used, i.e. generallyoverlying the index longitudinally.

The annular form of driver described is preferred because this providesan unlimited sequence of operations of either type in either directionand/or mixture thereof, for example a powered operation in one directionfollowed by a manual operation in the opposite direction and then arepeat of that sequence any number of times will rotate annulus 20 sothat teeth 32 pass index 40 in succession. Such mixed operations are notalways possible with the case with known power actuators, some of whichrequire an "idle" power or manual operation to reset the mechanism ifcertain logic is not followed, e.g. if the power unlocking is notfollowed by a power locking and this can be frustrating to the user. Incomparison a locking system incorporating the invention will besubstantially foolproof and user friendly.

It is to be understood that the invention contemplates other forms ofdriver and/or index than those described above although the latter areseen as desirable for giving all the stated advantages. Thus, the drivercould take the form of a slider guided for rectilinear movement in afirst path and driven by a push-pull or plunger type motor such as apneumatic or hydraulic ram, the index acting between opposing abutmentsprovided with at least one tooth and at least one opposing notch. Saidindex would be connected to a suitable output element such as a slideror lever arm, the index being controlled by formations of a fixedmounting and having resilient loading engaging it with one or other sideof the tooth and prevented from disengagement under the principlesdescribed above during power actuation but permitting indexing from sideto side of the tooth under movement of the output element by co-actingwith said notch during manual operation. Drivers having arcuate abutmentformations with one or more teeth and/or notches are also contemplated.

I claim:
 1. A power actuator (10) for shifting vehicle door lock or other closure mechanism selectively between a locked or other first condition and an unlocked or other second condition by powered operation while permitting manual operation also for effecting said shifting, said actuator comprising:(a) an operatively fixed mounting (12); (b) a driver (20) guided on said mounting for powered movement in a first path; (c) an output element (60) for attachment to said closure mechanism in use and guided for movement in a second path between first and second positions, said manual operation causing said movement; and (d) an index (40) in coacting relationship with the driver and the output element to transmit powered movement of the driver to the output element to move the latter between said positions, the driver having abutment portions which comprise at least one indexing formation (32), the index being resiliently urged longitudinally towards said formation, and the index having a head end (42) shaped to engage on one or other side of said formation to effect indexing of the output element positively to one or other position as manual operation displaces the output element and index relative to the driver:characterized in that said abutment portions are spaced across the first path in opposing relationship, one said abutment having said at least one indexing formation in the form of a tooth projecting towards the second abutment, and the second abutment having at least one notch (28) opposite said tooth; the index being located lengthwise between the abutment portions with motion transmitting connection to the output element allowing limited freedom of lateral movement of the index relative thereto, a tail end (44) of the index entering said one notch during a median part of said indexing to permit longitudinal displacement of the index allowing it to pass said tooth, said engagement of the head on a side of said tooth transmitting the powered movement of the driver to the output element positively through the index while moving the tail end laterally out of alignment with the or any said notch so that the second abutment prevents longitudinal displacement of the index which would free the head end from said tooth.
 2. An actuator as claimed in claim 1, wherein the driver is an annulus, said first and second abutment portions being constituted by generally diametrally opposing interior wall portions of the annulus, the index being received within the annuls and the powered movement of the latter being rotational so that said first path of movement is circular about the axis of the annulus.
 3. An actuator as claimed in claim 2, wherein said annulus is powered. by an electric motor having a worm pinion engaging an externally toothed periphery of said annulus.
 4. An actuator as claimed in claim 3, wherein a helix angle of the worm pinion is selected to permit driven rotation thereof by rotational force above a selected value applied to the annulus to enable manual release of the mechanism in the event of a failure of power operation while the index is in positive engagement between the annulus and output element.
 5. An actuator as claimed in claim 2, wherein the output element is a lever one arm of which is directly or indirectly coupled to the index for movement therewith.
 6. An actuator as claimed in claim 5, wherein said lever is fulcrummed co-axially with the annulus.
 7. An actuator as claimed in claim 5, wherein said lever is fulcrummed upon an axis spaced from the axis of the annulus.
 8. An actuator as claimed in claim 7, wherein said axis of the lever is outside the envelope of revolution of the annulus.
 9. An actuator as claimed in claim 2, wherein the annulus is provided with a series of equi-angularly spaced teeth and notches right around its interior periphery, the teeth being in one axial zone of said periphery and the notches, each being diametrically opposite a respective tooth, being in another axial zone thereof, the head and tail of the index being in stepped relationship in the diametrical plane for alignment with the respective axial zones.
 10. An actuator as claimed in claim 1, wherein the mounting includes slots or other guide formations with which control portions of the index engage to define the displacement of the latter relative to the drive during operation. 